1. Field of the Invention
The present invention relates to a rotary piston internal combustion engine having an oil-cooled piston journalled by a friction bearing, plane, sliding or sleeve bearing in a housing which consists of two side parts and a casing mantle part with dual-arc trochoidal-shaped casing mantle runway inner surfacing. An eccentric shaft journalled in the side parts passes axially through the housing. An eccentric on the eccentric shaft has a triangular pist n rotating as controlled by a synchronous transmission gear drive unit which is provided in the piston between the eccentric and one of the side parts. The synchronous transmission gear drive unit is formed by a hollow gear stationary or fixed on the piston and a pinion fixed or stationary on the housing located around the eccentric shaft.
2. Description of the Prior Art
Conventionally the lubricating- and coolingoil with such machines is supplied via axial and radial bores in the shaft into the slide bearing of the eccentric and from there into the cooling hollow chambers of the piston as well as directly into the transmission gear drive unit and to the outer side of the piston. Both the bearing lubrication as well as the cooling of the piston require a very considerable through-passage or volume of oil under pressure, which penetrates between the piston- and housing-sidewalls and there must be kept away from the working chambers and combustion procedures by oil inner seals, so-called scraper rings, in order not to cause intolerable exhaust or waste gas values. The oil inner seals however are costly and complex and additionally are not reliable. Furthermore, these oil inner seals require structural space between the hollow gear of the transmission drive unit and the axial gas seals and with that also restricting or narrowing other constructive possibilities.